N klA Case Report on a IV-degree Thermal Crush Injury of Right Upper Arm: The Application of Functional Prosthesis Implantation Technology.

Severe IV-degree thermal crush injury of limbs involved the subcutaneous fascia, muscle and bone, which may lead to amputation and has a great impact on the patient's quality of life. We can repair wounds with pedicle flaps or even free flaps, However, there are still huge challenges in bone defect of extremities and functional reconstruction. In recent years, with the development of functional prostheses, we have reconstructed limb functions in many patients helping them to complete their daily lives. We report a case where the right upper arm was injured by thermal crush, leading severe burns to the skin, fascia, muscle and bone. We applied a pedicled latissimus dorsi flap and a free anterolateral thigh flap to repair the wound, and realized the function of limb salvage and movement of the right upper arm by implanting 3D printed scapula, upper arm, and elbow joint prostheses. This case illustrates that IV-degree burns involving bones have new technologies to repair and achieve mobility now.

Interleukin-35 Attenuates D-Galactosamine/Lipopolysaccharide-Induced Liver Injury via Enhancing Interleukin-10 Production in Kupffer Cells.

Interleukin (IL) -35 is an anti-inflammatory cytokine which exerts various beneficial effects on autoimmune diseases. However, whether IL-35 plays a role in endotoxin induced hepatitis demands clarification. This study aims to reveal the effect and mechanism of IL-35 on endotoxin induced liver injury. Acute hepatic injury was induced by D-galactosamine (D-GalN, 400 mg/kg) and lipopolysaccharide (LPS, 5 µg/kg) administration in mice. IL-35 treatment ameliorated D-GalN/LPS induced liver injury in a dose dependent manner as shown by histological examination, ALT determination and Caspase-3 activity assay. It also reduced production of pro-inflammatory cytokines, tumor necrosis factor (TNF)-α, IL-1ß, and IL-6, and increased production of anti-inflammatory cytokines, IL-4, IL-10, and transforming growth factor (TGF)-ß. This hepato-protective effect was proved mainly mediated by Kupffer cells (KC) via gadolinium chloride depletion and cell adoptive transfer experiment. In addition, IL-35 emolliated the cytotoxicity of LPS-triggered KCs to hepatocytes, suppressed nitric oxide (NO) and TNF-α production, and elevated IL-10 production in LPS stimulated KCs. Furthermore, IL-35 could not exert hepato-protective effect in IL-10-deficient mice in vivo and it could not suppress LPS induced NO and TNF-α production in IL-10-deficient KCs in vitro. In conclusion, IL-35 protects endotoxin-induced acute liver injury, which mainly acts thought increasing IL-10 production in KCs. This finding demonstrates a role of IL-35 in anti-infectious immunity and provides a potential therapeutic target in treating fulminant hepatitis.

Use of Amniotic Microparticles Coated With Fibroblasts Overexpressing SDF-1α to Create an Environment Conducive to Neovascularization for Repair of Full-Thickness Skin Defects.

As angiogenesis and vasculogenesis involve the complex network structures of various types of cells, extracellular matrix components, and cytokines, it is still difficult to exactly mimic the microenvironment of vascularization in vivo. In our study, we constructed a complex containing highly proliferative fibroblasts that can secrete extracellular matrix components and growth factors to chemotaxize endothelial progenitor cells (EPCs) in an attempt to create an ideal microenvironment for quick vascularization. Amniotic membrane microparticles (mAM) rich in type IV collagen (COL IV) and laminin (LN) were prepared, and human dermal fibroblasts (HDF) were infected with lentivirus (LV) of overexpression of SDF-1α to construct SDF-1α(ov)HDF. Using the rotary cell culture system (RCCS), mAM was loaded with HDF or SDF-1α(ov)HDF to construct HDF-mAM and SDF-1α(ov)HDF-mAM complexes. The complexes were able to secrete various types of active peptides (IL-6, IL-8, TGF-ß, and bFGF) during in vitro culture. In addition, SDF-1α(ov)HDF-mAM complex highly expressed SDF-1α. Transwell assay showed SDF-1α(ov)HDF-mAM complex had an apparent chemotactic effect on EPCs. Transplantation of complexes onto full-thickness skin defects of C57BL mice further demonstrated that SDF-1α expression and the number of peripheral EPCs at days 3, 5, and 7 in the SDF-1α(ov)HDF-mAM group were significantly higher than that in other groups (p < 0.01). The local microvascular density at day 10 of transplantation showed that the microvascular density in the SDF-1α(ov)HDF-mAM group was significantly higher than that in HDF-mAM group (p < 0.01). In conclusion, HDF-mAM had a strong proliferative activity and could be used to create a sound microenvironment for quick vascularization by secreting multiple cytokines and extracellular matrix components. Overexpression of SDF-1α could chemotaxize EPCs to reach local wounds, thus further accelerating angiogenesis in the transplant site. The technique described may prove to be a new model for accelerating vascularization of tissue and organ transplants and chronic ischemic wounds.

A new method of wound treatment: targeted therapy of skin wounds with reactive oxygen species-responsive nanoparticles containing SDF-1α.

OBJECTIVE: To accelerate wound healing through promoting vascularization by using reactive oxygen species (ROS)-responsive nanoparticles loaded with stromal cell-derived factor-1α(SDF-1α). METHODS: The ROS-reactive nanomaterial poly-(1,4-phenyleneacetone dimethylene thioketal) was synthesized, and its physical and chemical properties were characterized. ROS-responsive nanoparticles containing SDF-1α were prepared through a multiple emulsion solvent evaporation method. The loading capacity, stability, activity of the encapsulated protein, toxicity, and in vivo distribution of these nanoparticles were determined. These nanoparticles were administered by intravenous infusion to mice with full-thickness skin defects to study their effects on the directed chemotaxis of bone marrow mesenchymal stem cells, wound vascularization, and wound healing. RESULTS: The synthesized ROS-reactive organic polymer poly-(1,4-phenyleneacetone dimethylene thioketal) possessed a molecular weight of approximately 11.5 kDa with a dispersity of 1.97. ROS-responsive nanoparticles containing SDF-1α were prepared with an average diameter of 110 nm and a drug loading capacity of 1.8%. The encapsulation process showed minimal effects on the activity of SDF-1α, and it could be effectively released from the nanoparticles in the presence of ROS. Encapsulated SDF-1α could exist for a long time in blood. In mice with full-thickness skin defects, SDF-1α was effectively released and targeted to the wounds, thus promoting the chemotaxis of bone marrow mesenchymal stem cells toward the wound and its periphery, inducing wound vascularization, and accelerating wound healing.

[Analgesic and sedative effects of inhaling a mixture of nitrous oxide and oxygen on burn patient during and after dressing change].

OBJECTIVE: To investigate the analgesic and sedative effects of inhaling a mixture of nitrous oxide and oxygen on burn patient during and after dressing change. METHODS: A total of 240 burn patients hospitalized in the Institute of Burn Research of Changhai Hospital Affiliated to the Second Military Medical University, Department of Burns of the First People's Hospital in Zhengzhou, and Department of Burns and Plastic Surgery of General Hospital of Ningxia Medical University from October 2011 to September 2012 were enrolled in our study, and they were all in accordance with the inclusion criteria. The 240 patients were divided into control group (n = 60, treated with inhalation of oxygen during dressing change) and treatment group (n = 180, treated with inhalation of a mixture of 65% nitrous oxide and oxygen during dressing change) according to the computer-generated list of random number. The other treatments in control group and treatment group were the same. Before, during, and after dressing change, heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), oxygen saturation (SO2), and adverse effects were observed. The degree of pain and anxiety felt by the patients were respectively evaluated with the visual analogue scale (VAS) and Chinese version of the burn specific pain anxiety scale (C-BSPAS) at the same time points as above. Data were processed with analysis of covariance, chi-square test, analysis of variance, and rank sum test. RESULTS: There were no significant differences between control group and treatment group in the levels of HR, SBP, DBP, and SO2 before dressing change (with F values respectively 0.76, 0.06, 1.11, 0.70, P values all above 0.05). Compared with those of control group, the levels of HR, SBP, DBP, and SO2 in treatment group were significantly ameliorated during dressing change (with F values respectively 81.78, 146.36, 226.44, 205.62, P values all below 0.01). After dressing change, the levels of DBP in the two groups were close (F = 0.31, P > 0.05), but the levels of HR, SBP, and SO2 showed statistical differences (with F values respectively 7.02, 8.69, 12.23, P < 0.05 or P < 0.01). Before dressing change, the VAS scores were approximate between control group and treatment group (Z = 0.21, P > 0.05). Compared with those in control group (9.4 ± 0.7, 1.7 ± 2.5), the VAS scores were significantly lowered in treatment group during and after dressing change (1.6 ± 1.3, 0.7 ± 1.1, with Z values respectively 11.84, 3.35, P values all below 0.01). There was no significant difference in C-BSPAS score between control group and treatment group before dressing change (Z = 0.62, P > 0.05). Compared with those in control group (75 ± 13, 73 ± 12), the C-BSPAS scores in treatment group were decreased during and after dressing change (9 ± 15, 9 ± 14, with Z values respectively 11.91, 12.28, P values all below 0.01). There were no obvious adverse effects in two groups before, during, and after dressing change. CONCLUSIONS: A mixture of nitrous oxide and oxygen seems to have obvious analgesic and sedative effects on burn patients during dressing change, and it can be widely used.

Role of inhibition of p38 mitogen-activated protein kinase in liver dysfunction after hemorrhagic shock and resuscitation.

BACKGROUND: The liver is one of the organs most frequently affected by trauma and hemorrhagic shock; the exact role of p38 mitogen-activated protein kinase (MAPK) activation in response to hepatic hemorrhagic shock/resuscitation (HS/R) remains unclear. MATERIALS AND METHODS: C57Bl/6 mice were divided into four groups: sham-operated group, SB-only group, control group, and SB + HS/R group. Hepatocellular injury (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]) and tumor necrosis factor (TNF-α) and interleukin (IL-1ß) messenger ribonucleic acid (mRNA) expression in the liver were assessed 6 h after resuscitation, p38 MAPK activation in the liver was assessed at 30 min after resuscitation. RESULTS: p38 MAPK activation was higher in the control group than other groups 30 min after resuscitation. p38 MAPK activation level in the SB + HS/R group did not change significantly compared with that of sham and SB-only groups, but was significantly lower than that in the control group. The TNF-α mRNA expression in the control group was significantly higher than that in the sham group. The TNF-α mRNA levels after HS/R in the SB + HS/R group were significantly lower than those in the control group and were roughly the same as those in the sham and SB-only groups. IL-1ß mRNA expression showed similar changes in the four groups. Serum ALT and AST levels in the control group were significantly higher than those in the sham group. The increase in serum ALT and AST levels after HS/R in the SB + HS/R group was significantly less pronounced than that in the control group and markedly higher than that in the sham group. CONCLUSIONS: p38 MAPK was phosphorylated during the HS/R process. Inhibiting the activation of p38 MAPK may attenuate HS/R injury to the liver.

An epidermal stem cells niche microenvironment created by engineered human amniotic membrane.

How to amplify epidermal stem cells (ESCs) rapidly is a challenging crux in skin tissue engineering research. The present study describes the preparation of 3D micronized (300-600 µm) amniotic membrane (mAM) by means of repeated freeze-thawing cycles to deplete cell components and homogenized with a macrohomogenizer in liquid nitrogen. This newly prepared mAM not only possessed the characteristics of a microcarrier but completely retained the basement membrane structure and abundant active substances such as NGF, HGF, KGF, bFGF, TGF-ß1 and EGF in the AM matrix. The result showed that mAM combined with rotary cell culture system (RCCS) was able to amplify ESCs quickly. The relative cell viability at day 7 and 14 was significantly higher than that of the conventional 2D plate culture (326 ± 28% and 535 ± 47% versus 232 ± 21% and 307 ± 32%, P < 0.05). In addition, the new method was able to prevent cell differentiation effectively and retain the characteristics of stem cells. When mAM loaded with ESCs (ESC-mAM) was further transplanted to full-thickness skin defects in nude mice, ESCs survived well and formed a new epidermis. Four weeks after transplantation, papilla-like structures were observed, and collagen fibers were well and regularly arranged in the newly formed dermal layer. In conclusion, the mAM as a novel natural microcarrier possesses an intact basement membrane structure and bioactivities. It not only provides the microenvironment similar to the stem cell niche within the human body favorable for ex vivo culture and amplification of ESCs but can be used as the dermal scaffold in constructing a skin substitute containing ESCs for the repair of full-thickness skin defects.

A new strategy of promoting vascularization of skin substitutes by capturing endothelial progenitor cells automatically.

How to promote vascularization of a skin substitute is the key to successful skin transplantation. Current methods are mainly through releasing angiogenesis-related factors (ARF) or seeding angiogenesis-related cells (ARC), but the efficacy of these methods is not satisfactory, because angiogenesis needs participation of multiple factors, extracellular matrix and related cells. The latest research has demonstrated that endothelial progenitor cells (EPCs) originating from bone marrow and existing in peripheral blood are the key element participating in revascularization of adult tissues. They directly participate in both stem cell vasculogenesis of ischemic tissues and local angiogenesis. We therefore hypothesize whether it is possible to construct a new skin substitute and use it to mobilize EPCs in bone marrow to peripheral circulation and capture EPCs automatically as a simple and effective method of promoting vascularization of the skin substitute for the sake of improving its post-transplant survival.

[Repair of deep burn and traumatic wounds in lower extremities with combined transplantation of multiple pedicled skin flaps].

OBJECTIVE: To summarize the clinical experience in repair of deep burn and traumatic wounds with combined transplantation of different types of pedicled skin flaps in lower extremities. METHODS: Two hundred and thirty-six patients with 271 deep wounds in lower extremities after burn or trauma were repaired with muscular skin flaps, local fascial flaps and island flaps with vascular pedicle (more than 20 types) in our department from Jan. 1998 to Sept. 2008. RESULTS: Complete necrosis of skin flaps occurred in 1 case, congestion and necrosis over the edge of skin flaps occurred in 3 cases, which were healed after grafting, and other skin flaps survived well with soft texture. Skin flaps were too bulky in 26 cases, among them 17 cases were thinned, and the appearance of other skin flaps were satisfactory. In 68 patients with functional region injury were recovered to certain extent without contracture. CONCLUSIONS: Skin flaps with pedicles, multiple transplantations if necessary, can repair deep wounds satisfactorily in lower extremities after deep burn or trauma injury.

[Skin tissue engineering in China].

Great progress has been made in the basic research and clinical application of skin tissue engineering in China over the past 20 years. It includes culture of epithelial cells and their preliminary clinical use, research and development of various dermal substitutes such as acellular dermal matrix, spongiform collagen membrane and high molecular weight polymer membrane, and modification of physical properties of dermal substitutes for the sake of raising their bioaffinity and vascularization, based on which composite skin containing epithelial cell layers has been constructed and used successfully in the repair of full-thickness skin defects. More recently, greater efforts have been made in the study of new epithelial seeding cells such as epithelial stem cell and hair follicle stem cell. With the work going into the center, it is hopeful into constructing an artificial skin that mimics the normal human skin in terms of structure and function with better viability of the transplant, so that it can eventually be used in clinical practice as a skin source for large area deep burn patients to improve the wound healing quality.

[Reconstruction and transplantation of the composite skin comprising epithelial growth factor gene-transfected keratinocytes].

OBJECTIVE: To investigate the epithelial growth factor (EGF) expression of EGF gene-transfected keratinocytes and its effect on cell proliferation after grafting. METHODS: Newborn Balb/c mouse keratinocytes and gene transfected keratinocytes were seeded on the surface of acellular dermal matrix and cocultured in different ratios as follows: 1:1, 1:3, or 1:5 1 week after culture. The composite skin was grafted onto the full-thickness wound in Balb/c mouse. Specimen was harvested at interval after grafting and underwent the immunohistochemistry staining for EGF and proliferating cell nuclear antigen (PCNA). RESULTS: Immunohistochemical staining showed EGF was expressed in the newly generated epidermis 1-2 week after grafting of the composite skin comprising Balb/c mouse keratinocytes and gene-transfected keratinocytes (at the ratio of 1:5). One week after surgery, Anti-PCNA positive basal cells were more than that in composite skin containing Balb/c mouse keratinocytes alone (P<0.01). CONCLUSION: The gene-transfected keratinocytes expresses EGF and promotes the proliferation of keratinocytes in the early stage after transplantation.

[Experimental study on preparing chitosan-collagen matrix and subcutaneous implantation].

OBJECTIVE: To investigate the feasibility of the chitosan-collagen membrane (CCM) as a dermal substitute. METHODS: Fresh bovine tendo calcaneus collagen was dispersed in 0.5 mol/L acetic acid, co-precipitated with chitosan and lyophilized. Dry membranes were cross-linked in 0.05% glutaraldehyde for 24 hours. In vitro its degrading rate was measured by use of collagenase degrading test. The chitosan-collagen membrane was implanted to subcutaneous dorsal sites of SD rats. After implantation, histocompatibility, vascularity and degradation were observed in vivo. RESULTS: The chitosan-collagen membrane was yellowish, translucent, and porous. Pore size ranged 50-250 microns, and collagen fiber bundles were reticular arrangement in the membrane. It had slower degradation than pure collagen membrane by collagenase in vitro. Subcutaneous implantation test showed the minimal inflammation, good histocompatibility and earlier vascularization. The membrane degradation was slower in vivo. Eight weeks after implantation, organized collagen structure was retained. CONCLUSION: The chitosan-collagen membrane has better physical and biological properties, ideal histocompatibility, earlier vascularization and slower degradation. Therefore, It is an optimum substitute for dermal scaffold.

[Experimental study on transplantation of acellular xeno-dermis and suspended keratinocytes].

OBJECTIVE: To investigate the outcome and histological changes of transplantation of acellular xeno-dermis combined with suspended keratinocytes. METHODS: Forty-two nude mice with full-thickness skin defect on the back were randomly divided into 2 groups, then acellular xeno-dermisand and suspended keratinocytes were adopted to cover the skin defect in the experimental group, pure suspended keratinocytes in the control group. The area of wound healing was calculated 2, 3 and 5 weeks after transplantation, and the rates of wound contraction were also calculated, and biopsy for histological examination was performed 3, 6 and 12 weeks after transplantation. RESULTS: Compared with the experimental group, the control group showed delayed wound healing (P < 0.05), intensive wound contraction (P < 0.05), poor durability, elasticity, and cosmetic appearances as well as disordered collagen fibers. In contrast, it was observed that the proliferation of collagen fibers was regularly organized, with no obvious acute immuno-rejection responses in the experimental group. CONCLUSION: The composite transplantation of acellular xenodermis and suspended keratinocytes could promote the wound healing with a satisfactory outcome.